1. Field of the Invention
The present invention relates to an aircraft lamp which includes a discharge lamp and reflector in a lamp housing.
2. Related Art
Conventionally, there have been known lamps employing discharge lamps as light sources which are used as exterior lamps attached to exterior portions of a body of an aircraft. For example, Japanese Patent Unexamined Publication JP-A-2001-266603 describes a searchlight which includes a housing, which is attached to an exterior portion of a body of a helicopter or an airplane, and a discharge lamp and a reflector, which are housed inside the housing. In addition, Japanese Patent Unexamined Publication JP-A-1-279503 describes a technique for a recognition light for an aircraft in which a reflecting film (a cold mirror), which can transmit infrared radiation, is provided on a reflector for transmitting heat generated in a light source to the rear of the reflector, so as to suppress the increase in temperature in front of the reflector.
Incidentally, although it is normal practice to use a discharge lamp together with an igniter for instantaneous activation, in the event that the igniter is installed in a position in an interior of the body of an aircraft, which lies far away from the discharge lamp, the starting voltage tends to drop easily. For example, in the case of an aircraft exterior lamp to which a high power (for example, 250 W) is supplied, due to an igniter generating a high-voltage pulse of the order of ±18 KV, in the event that this starting voltage drops, the burning capability of the discharge lamp is lowered. Consequently, although it is desirable that the igniter is installed on the housing together with the discharge lamp, in such cases, the interior of the housing is heated to high temperatures by heat generated by the discharge lamp and heat generated by the igniter. In particular, in aircraft lamps in which a discharge lamp generating a large quantity of light and a high-output igniter are installed side by side in a housing of limited size, in addition to a heat resistant construction, a construction is required which ensures a high degree of insulation.
Further, as aircraft lamps of this type, conventionally, there have been known exterior lamps which are equipped at exterior portions of bodies of aircraft, and landing lights, tailplane lights, logo lights, searchlights and the like are included in those exterior lamps. For example, the JP-A-2001-266603 describes a searchlight which includes a housing, which is attached to an exterior portion of a body of a helicopter or an aircraft having starboard and port wings, and a discharge lamp and a reflector, which are housed inside the housing.
Incidentally, because aircraft lamps are kept lit over a long period of time, light sources and other constituent parts must be inspected periodically for repair and replacement. In addition, in a case where the next scheduled flight of an aircraft is imminent, the maintenance work needs to be carried out within a limited period of time. With the conventional aircraft lamps, however, in particular, detaching and re-attaching of electric wiring therefrom and thereto takes some labor hours, leading to a problem that many hours are required for maintenance thereof.